1. Field of the Invention
The present invention relates to a technique for spooling received electronic data to perform print processing.
2. Description of the Related Art
When a document generated by a personal computer is printed, the document is generally converted into Page Description Language (PDL) data, which can be interpreted by a printing apparatus (e.g., printer), which is one type of an information processing apparatus, via a printer driver. The PDL data thus obtained by the conversion is transferred to the printing apparatus. In the printing apparatus, the received PDL data is sequentially interpreted to form bitmap data to be printed on a sheet surface. Thus, the printing apparatus performs printing by interpreting a PDL instruction to convert the PDL instruction into an object rendering instruction.
On the other hand, the generated document may be distributed after being converted into an electronic file in a specific format. Such a format of the electronic file has been widely used by various venders because its specification has been opened to the public.
Particularly, as a mobile data communication device (e.g., personal digital assistant (PDA) device or smartphone) has spread in recent years, it has become common that a document is distributed after being converted into a Portable Document Format (PDF) file. Such a format of an electronic file may include a format configured to previously give several kinds of print setting information in the electronic file. If the printing apparatus supports the electronic file including the print setting information, print processing for the electronic file can be performed without using a printer driver. As a result, the print processing can be performed with the same operation feeling regardless of a type of the printing apparatus. Such a print mode is referred to as a direct print, for example.
Such an electronic file is to be handled differently from the above-mentioned PDL data in some points. For example, in the above-mentioned PDF file, the print processing cannot be started until the reception of the PDF file is completed. This is because in the PDF format, information representing the entire structure of the PDF file is defined to be positioned at the end portion of the file. More specifically, in the printing apparatus, the PDF file cannot be interpreted sequentially according to progress in receiving the PDF file. Therefore, processing for interpreting the PDF file is started after all data are stored (spooled) in a storage in the printing apparatus.
Thus, the printing apparatus requires a storage capacity capable of spooling entire data of at least one PDF file to realize the direct print of the PDF file.
Some recent printing apparatuses may previously include a large-capacity storage for the purpose of storing a plurality of electronic files received for print processing, or assuming a simultaneous operation by a plurality of users. In addition, some printing apparatuses may be configured to mount a portable storage (e.g., memory card such as universal serial bus (USB) memory) thereon and store electronic files in the storage.
If the large-capacity storage is mounted in the printing apparatus, however, manufacturing costs or operational costs may be increased. Therefore, it is desirable that a capacity of the storage to be mounted should be made as small as possible while the direct print function is achieved.
In view of reducing the capacity of the storage, there is provided an image processing apparatus discussed in Japanese Patent Application Laid-Open No. 2004-287763. This image processing apparatus requests a transmission source of an electronic file to convert the electronic file into a data format that can be sequentially processed, when the size of a usable storage becomes a predetermined size or less.
Requesting the transmission source to convert the electronic file into the data format that can be sequentially processed results in time and effort similar to those taken to install a printer driver into an apparatus serving as the transmission source of the electronic file. Further, communication traffic increases because both the electronic file and data obtained by the conversion are transmitted.
On the other hand, a general printing apparatus starts to generate an internal job (print job) at a timing of starting to receive print data. More specifically, the printing apparatus starts to generate the job at a timing of starting a network session for receiving the above-mentioned electronic file. Similarly, when the printing apparatus receives another electronic file while executing the job, for example, it also starts to generate a new job.
The printing apparatus receives each electronic file independently.
Therefore, the printing apparatus may complete receiving an electric file of a subsequent job earlier than an electric file of a preceding job. Here, the preceding job is a job started to be received earlier and the subsequent job is a job started to be received later. In such a situation, if a storage capacity for storing the electronic file in the preceding job is depleted (capacity shortage), the following problem may occur.
1. When the Subsequent Job is Subjected to Print Processing Earlier.
In the general printing apparatus, jobs are subjected to print processing in the order of being generated. More specifically, the electronic files are subjected to print processing in the order of reception start. If the subsequent job is subjected to print processing earlier, exceptional processing needs to be performed separately. If large amounts of small-sized PDF files are input (received), the print processing for the preceding job may not be started until the print processing for all the input PDF files is completed.
2. When the Subsequent Job is Canceled.
In this case, a mobile data communication device, which has transmitted the electronic file of the subsequent job, cannot be notified that the print job including the input (received) electronic file has been canceled because communication with the mobile data communication device has ended.
To cope with the above-mentioned problem, the number of jobs to be concurrently processed has conventionally been limited. More specifically, the printing apparatus has been configured to previously secure a storage area storing the electronic file at a timing when the reception of the electronic file has been started, reject the reception of the job when the storage area cannot be secured, or wait until the job is completed.
In the printing apparatus thus configured, the data size of the electronic file is unclear when the reception of the electronic file is started. Thus, a storage area corresponding to the maximum size (maximum data size) of the electronic file, which can be processed in the printing apparatus, is secured.
Even if the storage area corresponding to the maximum size of the electronic file that can be processed in the printing apparatus is secured when the reception of the electronic file is started, as described above, the following problem remains. In order to store a plurality of electronic files, a large-capacity storage area needs to previously be secured as an electronic file storage area. If the maximum size of the electronic file that can be processed in the printing apparatus is 2 [GB], for example, a storage area corresponding to the maximum size of 16 {GB] needs to previously be secured to enable the storage of the maximum of eight electronic files. However, the actual size of the electronic file actually received may be smaller than the maximum size described above in many cases. Therefore, there remains a problem that a large part of the storage area previously secured becomes useless.